Hello,

My very first flight with the DJI Avata almost went wrong. With the exception of takeoff in Normal mode, I flew the entire battery in Manual mode. After about 10 minutes of flying, I went behind a building and lost connection, RTH engaged, I stopped RTH once I regained connection and was high enough, switched back to Manual mode and the drone turned around and fell, I managed to recover it by pressing the safety button. In the photo, here is the alert message I received...

Do you have an explanation for this situation? What is the exact meaning of this alert message?

Have you got a video from goggles which tell you what was the level of Avata at that moment?
I think the battery was too low after you flew 10 minutes in manual mode, may be the RTH kicked in because the low battery.

Hi there. Thank you for bringing this inquiry to us. We do apologize for the inconvenience caused. Can you please confirm if you receive a message on the Goggles about Return to Home due to a low battery warning? Could you please provide us with a screen recording of your Goggles for us to check? Please note that you need to install an SD card on the Goggles for you to enable the Camera View Recording under Settings>Camera>Advanced Camera settings> Camera View Recording. Lastly, If using the manual mode when the battery is low, and the aircraft power output is limited, please fly with caution. Please keep us posted. Thank you.

i'd suggest to learn manual mode flying in the simulator before yoloing in the real life.
The Battery notification is normal. In reality it doesn't do much anything, only reminds you not to do stupid stuff because battery cannot take high load anymore (like any other cinewhoop when battery level gets down to less than N). Avata still flies fine down to 0%

DJI Paladin Posted at 11-5 21:39
Hi there. Thank you for bringing this inquiry to us. We do apologize for the inconvenience caused. Can you please confirm if you receive a message on the Goggles about Return to Home due to a low battery warning? Could you please provide us with a screen recording of your Goggles for us to check? Please note that you need to install an SD card on the Goggles for you to enable the Camera View Recording under Settings>Camera>Advanced Camera settings> Camera View Recording. Lastly, If using the manual mode when the battery is low, and the aircraft power output is limited, please fly with caution. Please keep us posted. Thank you.

Hello and thank you for your answer.

I did not record with the goggles but here is a video and a very precise description of what happened.

I was in manual mode...

1. @9:07 First battery level message; altitude 16m; battery 36%;

2. I began my left turn to return to home;

3. @9:31 During my left turn, I flew behind a building and lost connection... RTH started;

4. @9:50 I recovered connection and cancelled RTH; altitude 48m; battery 31%;

5. @10:18 Switching to Manual Mode; altitude 85m; battery 28%;

6. @10:25 The sticks were well positioned to switch to Manual Mode but the image of the sticks positioning remained on the goggles screen... The warning message: M mode throttle output restricted... appeared;

7. @10:30 The fall began;

8. @10:32 After pressing the Brake Button, the drone is stabilized in Normal Mode; altitude 52m; battery 26%;

The next day (yesterday actually), I was flying in Manual Mode and just after the first battery level message, the following warning message appeared again:

'Battery output power insufficient. M mode throttle output restricted for safety reasons'

I switched directly to Normal Mode and there was no incident.

I would like to know what is the exact behavior of the drone when this warning message appears. So far, this message has appeared on every flight.

hungdang Posted at 11-5 19:39
Have you got a video from goggles which tell you what was the level of Avata at that moment?
I think the battery was too low after you flew 10 minutes in manual mode, may be the RTH kicked in because the low battery.

The battery level is probably related to the incident but the problem is the behavior of the drone once this alert message is generated.

fansebae Posted at 11-6 00:09
i'd suggest to learn manual mode flying in the simulator before yoloing in the real life.
The Battery notification is normal. In reality it doesn't do much anything, only reminds you not to do stupid stuff because battery cannot take high load anymore (like any other cinewhoop when battery level gets down to less than N). Avata still flies fine down to 0%

Without wanting to sound arrogant, I am an experienced pilot. I've spent hours and hours on the simulator and I have the DJI FPV for two years. Never had a single crash with the DJI FPV so far. This is not a pilot error but a bizarre behavior of the drone in this specific situation and after this warning message.

Here is a video to explain why that happened.

You have the last 30seconds in your goggles saved even when not recording. You can show is that.

Nees Posted at 11-6 11:03
You have the last 30seconds in your goggles saved even when not recording. You can show is that.

If you watch my last video, the total flight time that day was 12:42 and the drone was stabilized @10:32. The last 30 seconds were the flight back to home point and landing.

CTT Channel Posted at 11-6 04:23
Without wanting to sound arrogant, I am an experienced pilot. I've spent hours and hours on the simulator and I have the DJI FPV for two years. Never had a single crash with the DJI FPV so far. This is not a pilot error but a bizarre behavior of the drone in this specific situation and after this warning message.

Can you share the full log (CSV) on Airdata? That'd paint a proper picture of what might have happened. RC and IMU data is in CSV, as are the messages, battery levels, etc.

fansebae Posted at 11-6 12:54
Can you share the full log (CSV) on Airdata? That'd paint a proper picture of what might have happened. RC and IMU data is in CSV, as are the messages, battery levels, etc.

It's something I've never had to do... I'll try.

fansebae Posted at 11-6 12:54
Can you share the full log (CSV) on Airdata? That'd paint a proper picture of what might have happened. RC and IMU data is in CSV, as are the messages, battery levels, etc.

Here is the link :

https://drive.google.com/file/d/ ... view?usp=share_link

FPVTrendz Posted at 11-6 10:19
Here is a video to explain why that happened.

https://youtu.be/-IEAO4qd54k

Just watched the video... It was interesting thanks for sharing.

CTT Channel Posted at 11-7 08:39
Here is the link :

https://drive.google.com/file/d/1g22brMC7JWwTsyMDXAaxBLuOyLV-Zz7m/view?usp=share_link

Ok. So in the log i can see the mode switch moved from  sport to manual. Then Pitch (elevator) is pushed fully forward(up) and throttle applied past centre point. Then sticks have been released, throttle brought down to hover level and drone has made a transition to manual mode. After that, the pitch is pushed fully forward again for a short period (300ms) and then pulled back again, and then switch has been triggered back to Normal mode.
According to the logged data, all mode changes, stick movements, and drone behaviour are as we see in the video. If it wasn't a pilot error, i would suggest to recalibrate the remote.

FPVTrendz Posted at 11-6 10:19
Here is a video to explain why that happened.

https://youtu.be/-IEAO4qd54k

Avata has voltage monitoring and different protection levels. Firs one kicks in at 3.6v and just notifies the pilot. Second one is triggered when cell voltage drops below 3.4v which forces drone to land. There's also a final protection, which will basically shut everything down and that's at 2.7v per cell.
Lowest cell voltage for CTT Channel's problematic flight is 3.4v under load on only one cell for just a moment at the end of the flight when braking after reaching the home point. So ... nothing special...

fansebae Posted at 11-7 23:56
Ok. So in the log i can see the mode switch moved from  sport to manual. Then Pitch (elevator) is pushed fully forward(up) and throttle applied past centre point. Then sticks have been released, throttle brought down to hover level and drone has made a transition to manual mode. After that, the pitch is pushed fully forward again for a short period (300ms) and then pulled back again, and then switch has been triggered back to Normal mode.
According to the logged data, all mode changes, stick movements, and drone behaviour are as we see in the video. If it wasn't a pilot error, i would suggest to recalibrate the remote.

Thank you for the analysis, it is very impressive. You seem to know a lot about this stuff.

After canceling the RTH, I switched to manual mode then you have to position the sticks to really engage the manual mode. I tried for a few seconds but the manual mode did not engage, when the procedure for positioning the sticks disappeared from the screen of the goggles, the drone immediately began its fall.

Anyway, I will recalibrate the R.C.

Today, the fourth day of flight with the DJI Avata, a second incident occurred.

After the first message relating to the battery level, I switched directly from manual mode to normal mode. Then, I flew to my Home Point (about 30 m), I pushed my left stick up to gain a little altitude, nothing happened, the drone remained hovering. Then, for about ten seconds, I pushed my stick fully forward(up), nothing happened, just hovering. Then I pushed my stick down and there, instead of going down, the drone went up, it stabilised for a few seconds then I had control of the drone again.

Can you check what happened?

Here is the link of the *csv file:

https://drive.google.com/file/d/ ... view?usp=share_link

Thanks again for your help.

CTT Channel Posted at 11-8 12:48
Thank you for the analysis, it is very impressive. You seem to know a lot about this stuff.

After canceling the RTH, I switched to manual mode then you have to position the sticks to really engage the manual mode. I tried for a few seconds but the manual mode did not engage, when the procedure for positioning the sticks disappeared from the screen of the goggles, the drone immediately began its fall.

Not CSV

fansebae Posted at 11-8 14:26
Not CSV

Sorry...

https://drive.google.com/file/d/ ... view?usp=share_link

CTT Channel Posted at 11-8 14:48
Sorry...

https://drive.google.com/file/d/1GL12kZIAnF7XSuJHf_BdQaMNHheTed-Q/view?usp=share_link

ok. i see everything happening as you described.
1. please learn to fly manual mode and understand the how thrust vectoring works. In manual mode there are little to no pilot "helpers" available. AHRS does not take into account compass or accelerometer. All depends on gyro and pilots throttle management is not for altitude per se, but is to vector thrust.
2. Aircraft went into "braking" mode due to low battery (yes yes, dji is over-protective in that sense). When braking mode is activated, the sticks input is ignored until FC considers AC "stable". Since you also had Low battery RTH active the inputs were extra slow, only to compensate AC landing procedure.
I find all that happened to you fairly normal. (and yes, i'm a pro cine pilot flying daily, not only dji and not just for fun).
NB, i won't be always here to analyze logs. Learn to understand what's in the logs ... and happy flying

fansebae Posted at 11-9 08:17
ok. i see everything happening as you described.
1. please learn to fly manual mode and understand the how thrust vectoring works. In manual mode there are little to no pilot "helpers" available. AHRS does not take into account compass or accelerometer. All depends on gyro and pilots throttle management is not for altitude per se, but is to vector thrust.
2. Aircraft went into "braking" mode due to low battery (yes yes, dji is over-protective in that sense). When braking mode is activated, the sticks input is ignored until FC considers AC "stable". Since you also had Low battery RTH active the inputs were extra slow, only to compensate AC landing procedure.

Apart from these incidents, I find that the drone flies well... The way the drone behaves at the end of the flight is totally different from the DJI FPV...

I was in normal mode during the second incident.

Thank you for your help, if everything seems normal to you, I feel reassured and I will adapt myself.

You seem like a real expert, do you have a YouTube channel? I think you could bring added value for a lot of people.